Sheet-Bulk Metal Forming of Preformed Sheet Metal Parts

2011 ◽  
Vol 473 ◽  
pp. 83-90 ◽  
Author(s):  
Thomas Schneider ◽  
Marion Merklein
Keyword(s):  
Sheet Metal ◽  
Deep Drawing ◽  
Metal Forming ◽  
Sheet Plane ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Sheet Metal Parts ◽  
Bulk Forming ◽  
Process Factors ◽  
Functional Components

Due to ecological and economic challenges there is a rising demand on closely-tolerated complex functional components. Regarding short process chains and improved mechanical properties conventional forming processes are often limited. A promising approach to meet these requirements can be seen in the combination of traditional sheet and bulk metal forming processes, to form sheet metals out of the sheet plane with typical bulk forming operations. The challenge of applying conventional bulk forming operations on sheet metal is the interaction between regions of high and low deformation, which is largely unknown in literature. To analyze this topic fundamentally, a process combination of deep drawing and upsetting is developed for manufacturing tooth-like elements at pre-drawn cups. To fully understand material flow out of the sheet plane into the tooth cavity and to identify and qualify process factors depending on the functional elements´ geometry and friction, a single upsetting stage forming a simplified model of the blank is virtually analyzed with finite-element simulation. By inhibiting the forming history of the pre-drawn blank, the upsetting process can be investigated without interactions with a previous deep drawing operation.

Locally Adapted Tribological Conditions as a Method for Influencing the Material Flow in Sheet-Bulk Metal Forming Processes

2015 ◽  
Vol 639 ◽  
pp. 267-274 ◽  
Author(s):  
Maria Loeffler ◽  
Thomas Schneider ◽  
Ulrich Vierzigmann ◽  
Ulf Engel ◽  
Marion Merklein
Keyword(s):  
Metal Forming ◽  
Material Flow ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Bulk Forming ◽  
Mould Filling ◽  
Stage Process ◽  
Functional Components ◽  
Process Combination ◽  
Abrasive Blasting

Due to ecological and economic challenges there is a growing demand for lightweight construction by using closely-tolerated complex functional components with variants. Conventional sheet and bulk metal forming operations are often improvident in producing such parts. A promising approach is the process-class “sheet-bulk metal forming” (SBMF). Within SBMF bulk forming operations are applied to sheet metals, often in combination with sheet forming operations [1]. This leads to a significant gradient in load conditions regarding stress and strain states and causes locally varying tribological conditions. Thus, the investigation of the tribological conditions and the provision of suited tribological systems are essential for the successful application of SBMF processes. The objective of the current study is the experimental investigation of the applicability of tribological adaptions by local abrasive blasting on a single-stage process combination of deep drawing and upsetting to produce a component with an external gearing. The manipulation of the local tribological conditions by the use of abrasive blasting leads to a better control of the material flow and in consequence to an improved quality of the components in terms of higher mould filling and cup heights, and a reduced thickening of the sheet in the area of the cup bottom.

Material Flow in Sheet-Bulk Metal Forming

2012 ◽  
Vol 504-506 ◽  
pp. 1035-1040 ◽  
Author(s):  
Ulrich Vierzigmann ◽  
Johannes Koch ◽  
Marion Merklein ◽  
Ulf Engel
Keyword(s):  
Sheet Metal ◽  
Metal Forming ◽  
Material Flow ◽  
Fe Simulation ◽  
Forming Process ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Mould Filling ◽  
Model Geometry ◽  
Functional Components

Innovative trends like increasing component functionality, the demand for automotive lightweight constructions and the economic issue to optimize existing process chains, require new ways in manufacturing. Today, the traditional sheet metal and bulk metal forming processes are often reaching their limits if closely-tolerated complex functional components with variants have to be produced. A promising approach is the direct forming of high-precision shapes starting from blanks. Thus, classic sheet metal forming operations, such as deep drawing, are combined with bulk metal forming operations like extrusion of complex variants as for example teeth. This combination of sheet and bulk metal forming operations leads to a side by side situation of different tribological conditions according to the locally varying load situations within the same forming process. This new class of forming processes is defined as sheet-bulk metal forming (SBMF). The tribological conditions in sheet-bulk metal forming processes are of major importance for the process realization, its stability and for the quality of the produced part. The objective of this paper is the investigation of material flow in SBMF in general and the attempt to improve the material flow by local adapted tribological conditions. First the material flow was analyzed by FE-simulation of a model geometry that is typical for SBMF. The investigations with FE-simulation have shown, locally adapted tribological conditions are leading to an improvement in material flow and thus to an increased mould filling. As frictional conditions are directly connected to the topography of workpiece and tool, the modification of the workpiece topography is leading to an alteration in friction values. For the modification of workpiece topography grit blasting was used. The increase in friction of grit blasted surface towards untreated surface was investigates by using the laboratory friction tests. To manufacture specimens with locally adapted topographies for forming tests a masking technique has been developed. The masks are designed after the preliminary findings determined by FE-simulation.

scholarly journals Influence of component design on extrusion processes in sheet-bulk metal forming

2019 ◽  
Vol 13 (6) ◽  
pp. 981-992 ◽  
Author(s):  
F. Pilz ◽  
M. Merklein
Keyword(s):  
Sheet Metal ◽  
Metal Forming ◽  
Experimental Approach ◽  
Functional Integration ◽  
Dimensional Accuracy ◽  
Design Parameters ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Bulk Forming ◽  
Component Design

Abstract Nowadays, the functional integration of workpieces challenges existing forming processes. The combination of established forming processes – like sheet metal and bulk forming – offers the possibility to counter this issue. The application of bulk forming operations on sheet metal semi-finished products, also called sheet-bulk metal forming (SBMF), is an innovative approach. The potential of SBMF cannot be fully exploited, as there are no recommendations in terms of workpiece design and layout influence on the process result. Therefore, this paper focuses on the analysis of semi-finished products and component design parameters on resulting part and process properties in two extrusion processes in SBMF. The investigation is based on a combined numerical and experimental approach. It is shown that the investigated design parameters, in addition to the achievable dimensional accuracy, substantially influence the occurring tool loads as well as the required process forces.

scholarly journals Material flow control in sheet-bulk metal forming processes using blasted tool surfaces

2018 ◽  
Vol 190 ◽  
pp. 13003 ◽  
Author(s):  
Marion Merklein ◽  
Maria Löffler ◽  
Daniel Gröbel ◽  
Johannes Henneberg
Keyword(s):  
Metal Forming ◽  
Material Flow ◽  
Simultaneous Occurrence ◽  
Tribological Behaviour ◽  
Forming Process ◽  
Functional Elements ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Main Challenge ◽  
Functional Components

Highly-integrated and closely-tolerated functional components can be produced by sheet-bulk metal forming which is the application of bulk forming operations on sheet metals. These processes are characterized by a successive and/or simultaneous occurrence of different load conditions such as stress and strain states which reduce the geometrical accuracy of the functional elements. Thus, one main challenge within sheet-bulk metal forming is the identification of methods to control the material flow and thus to improve the product quality. One suitable approach is to control the material flow by local modifications of the tribological conditions. Within this study requirements regarding the needed adaption of the tribological conditions for a specific sheet-bulk metal forming process were defined by numerical investigations. The results reveal that a local increase of the friction leads to an improved die filling of the functional elements. Based on these results abrasive blasting as a method to modify the tool surface and thus influencing the tribological behaviour was investigated. For the determination of the tribological mechanism of blasted tool surfaces, the influence of different blasting media as well as blasting pressures on the surface integrity and the friction were determined. The correlations between surface properties and friction conditions were used to derive the mechanisms of blasted tool surfaces.

scholarly journals Investigation on blasted tool surfaces as a measure for material flow control in sheet-bulk metal forming

2019 ◽  
Vol 6 ◽  
pp. 10 ◽  
Author(s):  
Marion Merklein ◽  
Maria Löffler ◽  
Daniel Gröbel ◽  
Johannes Henneberg
Keyword(s):  
Metal Forming ◽  
Material Flow ◽  
Simultaneous Occurrence ◽  
Tribological Behaviour ◽  
Bulk Metal ◽  
Geometrical Accuracy ◽  
Bulk Metal Forming ◽  
Tribological System ◽  
Local Modification ◽  
Functional Components

Highly integrated and closely tolerated functional components can be produced by sheet-bulk metal forming which is the application of bulk forming operations on sheet metal. These processes are characterized by a successive and/or simultaneous occurrence of different load conditions which reduce the geometrical accuracy of the parts. One challenge within sheet-bulk metal forming is the identification of methods to control the material flow to improve the product quality. A suitable approach is the local modification of the tribological conditions. Within this study, requirements regarding the needed adaption of the tribological system for a specific process were defined by numerical investigations. The results reveal that a local increase of the friction leads to an improved geometrical accuracy. Based on these results, abrasive blasting as a method to modify the tool surface and thus influencing the tribological behaviour was investigated. For the determination of the tribological mechanism of blasted tool surfaces, the influence of different blasting media as well as blasting pressures on the surface integrity and the friction were determined. Additionally, the functional stability of a modification was investigated. Finally, the correlations between surface properties and friction conditions were used to derive the mechanisms of blasted tool surfaces.

scholarly journals Extension of the forming limits of extrusion processes in sheet-bulk metal forming for production of minute functional elements

2020 ◽  
Vol 7 ◽  
pp. 9 ◽  
Author(s):  
Florian Pilz ◽  
Johannes Henneberg ◽  
Marion Merklein
Keyword(s):  
Sheet Metal ◽  
Metal Forming ◽  
Extrusion Process ◽  
Process Conditions ◽  
Functional Elements ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Lateral Extrusion ◽  
Component Design ◽  
Tailored Surfaces

Increasing demands in modern production pose new challenges to established forming processes. One approach to meet these challenges is the combined use of established process classes such as sheet and bulk forming. This innovative process class, also called sheet-bulk metal forming (SBMF), facilitates the forming of minute functional elements such as lock toothing and gear toothing on sheet-metal bodies. High tool loads and a complex material flow that is hard to control are characteristic of SBMF. Due to these challenging process conditions, the forming of functional elements is often insufficient and necessitates rework. This negatively affects economic efficiency. In order to make use of SBMF in industrial contexts, it is necessary to develop measures for improving the forming of functional elements and thereby push existing forming boundaries. This paper describes the design and numerical replication of both a forward and a lateral extrusion process so as to create involute gearing in combination with carrier teeth. In a combined numerical-experimental approach, measures for extending the die filling in sheet-metal extrusion processes are identified and investigated. Here, the focus is on approaches such as process parameters, component design and locally adjusted tribological conditions; so-called ‘tailored surfaces’. Based on the findings, fundamental mechanisms of action are identified, and measures are assessed with regard to their potential for application. The examined approaches show their potential for improving the forming of functional elements and, consequently, the improvement of geometrical accuracies in functional areas of the workpieces.

Machines and Tools for Sheet-Bulk Metal Forming

2011 ◽  
Vol 473 ◽  
pp. 91-98 ◽  
Author(s):  
Marion Merklein ◽  
A. Erman Tekkaya ◽  
Alexander Brosius ◽  
Simon Opel ◽  
Lukas Kwiatkowski ◽  
...  
Keyword(s):  
Metal Forming ◽  
Incremental Forming ◽  
Batch Size ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
New Process ◽  
Novel Approaches ◽  
The Individual ◽  
Forming Tools ◽  
Functional Components

The demand on closely-tolerated and complex functional components in the automotive sector, like e.g. synchronizer rings, leads to the development of a new process-class named “sheet-bulk metal forming”. Within this technology bulk metal forming operations are applied on sheet metals. In the following two novel approaches considering machines and tools for sheet-bulk metal forming are presented. The first approach aims on a technology based on rolling, which is suitable for mass production. The second one is an incremental forming solution for low batch production. Both machine concepts allow the application of different forming strategies to manufacture individual tailored semi-finished products in term of a pre-distribution of material. These products feature variable sheet thicknesses and mechanical properties, which can be adapted to their case of applica-tion. Depending on the individual batch size, the blanks can be finished to functional parts by sub-sequent forming processes like deep drawing and upsetting, extrusion or incremental forming. In this paper the case of an incremental tooth-forming is mainly considered. Forming sequences and resulting loads are modeled and calculated by finite elements simulations for all discussed processes to serve as a basis for the design and dimensioning of the machine components and forming tools.

New Criterion for Prediction of the Wrinkle Formation in Deep Drawing Process

2015 ◽  
Vol 651-653 ◽  
pp. 71-76 ◽  
Author(s):  
Mathias Liewald ◽  
Fei Han ◽  
Ranko Radonjic
Keyword(s):  
Sheet Metal ◽  
Deep Drawing ◽  
Metal Forming ◽  
Failure Modes ◽  
Limit Curve ◽  
Metal Part ◽  
Sheet Metal Parts ◽  
Forming Technology ◽  
Wrinkling Analysis ◽  
New Criterion

Wrinkling is one of the primary failure modes in deep drawing of sheet metal parts. Previous studies showed that the second principle stress can be a measure for the initiation and growth of wrinkles. The wrinkling analysis is usually made with using conical cup geometries. Recent experiments and numerical simulation results at the Institute for Metal Forming Technology (IFU) showed that the wrinkling analysis using simple conical cup geometries is not suitable for description of complex wrinkling conditions for real deep drawing processes. In the presented experimental results, fender shaped geometry was chosen as an example. During deep drawing of this geometry, different wrinkling formulation mechanisms were observed. Regarding these wrinkling mechanisms, a new wrinkling limit curve can be determined. By use of this new wrinkling limit curve, it is possible to detect the occurrence of wrinkles in each area of the formed sheet metal part until the wrinkle is finally formed.

scholarly journals Functional Analysis of Components Manufactured by a Sheet-Bulk Metal Forming Process

2021 ◽  
Vol 5 (2) ◽  
pp. 49
Author(s):  
Andreas Hetzel ◽  
Robert Schulte ◽  
Manfred Vogel ◽  
Michael Lechner ◽  
Hans-Bernward Besserer ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Metal Forming ◽  
Fatigue Behavior ◽  
Design Guidelines ◽  
Load Bearing Capacity ◽  
Bulk Metal ◽  
Load Bearing ◽  
Geometrical Properties ◽  
Bulk Metal Forming ◽  
Functional Components

Due to rising demands regarding the functionality and load-bearing capacity of functional components such as synchronizer rings in gear systems, conventional forming operations are reaching their limits with respect to formability and efficiency. One way to meet these challenges is the application of the innovative process class of sheet-bulk metal forming (SBMF). By applying bulk forming operations to sheet metal, the advantages of both process classes can be combined, thus realizing an optimized part weight and an adapted load-bearing capacity. Different approaches to manufacturing relevant part geometries were presented and evaluated regarding the process properties and applicability. In this contribution, a self-learning engineering workbench was used to provide geometry-based data regarding a novel component geometry with circumferential involute gearing manufactured in an SBMF process combination of deep drawing and upsetting. Within the comprehensive investigations, the mechanical and geometrical properties of the part were analyzed. Moreover, the manufactured components were compared regarding the increased fatigue strength in cyclic load tests. With the gained experimental and numerical data, the workbench was used for the first time to generate the desired component as a CAD model, as well as to derive design guidelines referring to the investigated properties and fatigue behavior.

Analysis of Effectiveness of Locally Adapted Tribological Conditions for Improving Product Quality in Sheet-Bulk Metal Forming

2015 ◽  
Vol 794 ◽  
pp. 81-88 ◽  
Author(s):  
Maria Löffler ◽  
Daniel Groebel ◽  
Ulf Engel ◽  
Kolja Andreas ◽  
Marion Merklein
Keyword(s):  
Metal Forming ◽  
Material Flow ◽  
Operating Time ◽  
Wear Behaviour ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Geometrical Features ◽  
Tailored Surfaces ◽  
Economic Developments ◽  
Functional Components

Due to current ecological and economic developments there is a growing demand for functional components with complex and closely tolerated geometrical features. Conventional sheet and bulk metal forming operations leads to products which are often limited in their geometrical and functional variety. A promising approach is the process-class sheet-bulk metal forming (SBMF). SBMF is characterised by the application of bulk and sheet forming operations on sheet metals [1]. This combination leads to locally and temporally varying load conditions regarding stress as well as strain states. In order to get high quality parts, controlling the material flow is of major importance. Modified Surfaces, so-called tailored surfaces represent an innovative approach to control the material flow. The objective of the current study is the experimental investigation of the effectiveness of locally adapted tribological conditions using workpiece-and tool-sided tailored surfaces within SBMF processes. The study has shown that the local adaption of workpiece and tool surface increased the heights of functional elements. Thus, using locally adapted tribological conditions leads to an improvement of the quality of the produced gearing components. In a further step the influence of surface modifications on the surface properties of the manufactured components are analysed. Additionally, investigations regarding the wear behaviour of tool-sided surface adaptions lead to the assumption, that the effectiveness of tailored surfaces is reduced during the operating time of the tools.

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